Dry concentrator



May 10, 1938.

J. G. WILSON l DRY CONCENTRATOR 2 Sheets-Sheet -1 May l0, 1938,. J. G. WILSQNl 2,116,815

` DRY CONCIENTRATOR Filed Sept. 19, 1936 2 Sheets-Sheet 2 gmc/WDM Jeff-P# Mao/1f Patented May 10, 1938 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to new and useful improvements in dry concentrators.

One object of the invention is to provide an improved device adapted for use in separating heavier mineral grains from a mass of dry material, whereby precious metals, such as gold, may be recovered without the use of water or other iiuids.

An important object of the invention is to provide an improved dry concentrator which is arranged to impart movement to the material to be separated and which is so constructed that the inertia of the mass of material is overcome, whereby progress of the material through the de vice is accelerated, and at the same time loosely consolidated masses of the material are disintegrated, thereby improving the degree of separation of the heavier mineral grains from the remainder.

Another object of the invention is to provide an improved dry concentrator having a series of stepped trays so arranged that the material placed therein will travel in one direction therethrough upon movement of the trays, and at the same time the higher gravity material will be restrained from such movement and retained in the trays, while the waste material will be voided from the trays without the use of agitating means other than the movement of said trays.

A further object of the invention is to provide an improved dry concentrator having a series of stepped trays, each tray being provided with a plurality of transverse bales which act to impart the movement of the tray to the material therein,

.so as to overcome the natural inertia of the material, whereby the separating action of the motion of the trays is distributed throughout the material in said trays.

A .still further object of the invention is to provide an improved device adapted for use in separating material of a higher specific gravity from a mass of dry material which may be easily adjusted for use with a large variety of materials.

Another object of the invention is to provide an improved dry concentrator which is portable and simple in structure, whereby manufacture is economical and replacement or repair of damaged parts may be readily accomplished.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and ,by reference to the accompanying drawings, in

which an example of the invention is shown, and wherein: i

Figure l is an isometric view, partly in section, of a concentrator constructed in accordance with the invention,

Figure 2 is an enlarged, transverse, vertical, sectional view of a portion of the stepped trays,

Figure 3 is a plan view of the frame and carriage,

Figure 4 is a plan view of the trays, 10

Figure 5 is a view taken on the line 5--5 of Figure 3, and

Figure 6 is a view taken on the Figure 3.

In the drawings, the numeral Il) designates a 15 series of elongate trays made of wood, or other suitable material, and arranged in stepped order, Each tray is formed with a back wall I I, a slightly inclined bottom I2 and a front wall, the back wall of each tray forming the front wall of the tray next above, whereby the upper edge of the front wall of each tray is lower than the upper edge of its back wall, as best shown in Figure 2. Side walls I3 common to all the trays are provided, each side wall having its upper edge inf clined at substantially the same angle as the inclination of the stepped trays. 'Ihe back wall i4 of the uppermost tray has its upper edge iiush with the upper edges of the side walls` I 3, said line 6-6 of walls thereby forming in effect an inclined trough 30 in which the trays are positioned. If desired, the walls and bottom of the trays may be covered with a suitable sheathing I5 conforming to the shape of the trays and extending throughout the series as shown in Figures l and 2. It is noted 3.- that the sheathing is not necessary to the invention but may be used if desired.

Elongate inclined tray supporting bars I6 are secured to the underside of the trays by screws or other means and lie contiguous to the side 40 walls I3, being suitably fastened to said side walls. Vertically extending posts Il have their upper ends suitably secured, as by bolts Il', to the rear end of each supporting bar and are of such length that the front and rear walls of each tray lie in a substantially vertical plane. It is noted, however, that the inclination of the series of trays may be varied by varying the height of the vertical posts I'I.

A suitable baffle supporting frame I 8 is pro- 50 vided for insertion int-o the trays, and includes suitable side frame members I9 which have their lower portion bent to conform to the stepped trays in cross-section. The upper portion of each side member is formed so as to lie approximately l transverse rods 2l are so positioned on the longiparallel to the upper edge of the side walls I3. The side members are connected by horizontal rods 2t, which extend longitudinally of the trays and have .substantially the same length as the trays whereby the side members I9 are held in engagement with the side walls I3 of the trays. In each tray the horizontal rods 20 are shown as four in number, two having their ends secured to the side members IS below the upper edge of the front wall of the tray so as to be slightly spaced from the bottom of the tray; the other two horizontal rods have their ends secured to the side members so as to lie in a plane slightly above the upper edge of the front wall of the tray, as clearly shown in Figure 2. It is noted that the frame IB is not secured to the trays but is held in position by frictional engagement with the walls of the trays.

A plurality of spaced transverse baffles 22 are provided within each tray, and are supported upon transverse rods 2l which have their ends secured to the longitudinal rods 20. It will be seen, therefore, that the baffles divide each tray into a plurality of compartments, and. it is preferable that, in each adjoining tray, the baffles be arranged in staggered relation (Figure 4), though any suitable arrangement may be used. The bales are preferably made of some foraminous material, such as coarse wire screen, but any suitable material may be used. It is noted that the tudinal rods 2@ that a space is formed between the bottoms of the baies and the bottom of the tray, as clearly shown in Figure 2. While the baflies have been described as carried by a suitable frame i3, it is obvious that the baffles could be Secured to the front and back walls of each tray, thereby eliminating the use of said frame. It has been found advantageous, however, to use the frame, since the baffles may be more readily positioned within, or removed from, the trays when carried by said frame, and thus, baliies of various sizes and disposition or location may be used in the trays.

in operation, the mass of material to be separated is fed, preferably in a steady stream, into the uppermost tray, while a horizontally reciprocating motion in a longitudinal direction, is applied to the trays. It will be seen that the baffles carried within each tray will be moved therewith, and each baffle will act upon the material in the vicinity thereof to impart motion thereto, whereby said material will be agitated .and the heavier grains sifted to the bottom of the tray, while the vlighter or waste material will rise to the top and be voided over the lower front wall of each tray into the tray next below. The motion of the trays causes the material therein to pile up against the baffles, whereby a portion of the lighter particles, which are on top, will naturally fall over the low front wall of the tray into the next lower tray. It is obvious that any loosely consolidated mass of material being struck by one of the baliles will be disintegrated, thereby accomplishing a more complete separation of the material. As hereinbefore stated, the heavier, or valuable, material will be sifted, due to the motion of the trays, to the bottom thereof, where it will be restrained from movement down the steps of the trays by their forward walls, while the space between the bottoms of the baffles and the bottom of the tray additionally serves to retain said heavier grains by allowing them to acquire a natural inertia to agitation, thereby escaping the agitating action of the baffles which would tend to move Said heavier grains into the next lower tray.

It will be seen, therefore, that the baflles act upon the material Within the trays to accelerate the separation thereof, as well as to accelerate the movement of the material through the device by acting as banking walls which tend to void the lighter waste material over the front `walls of the trays. It is further noted that any desired arrangement of the baflles may be obtained by using a frame having said arrangement secured thereto, and since the frames are removable substitution of any one arrangement for another is facilitated.

Any suitable means may be used for transmitting a reciprocating motion to the trays, whereby said trays are made to reciprocate longitudinally, but the means illustrated and hereinafter described has been found satisfactory and desirable.

A frame 30, substantially rectangular in shape and made of wood or other suitable material, rests upon blocks 30. A pair of parallel arms or extensions 3l extend laterally from one side of the frame and have a crankshaft 32 journaled in their outer ends.

A suitable carriage 33 lies within the frame 30, and includes a plurality of horizontal supporting bars 33 supported on bearings 34 which are slidable on transverse carriage guide shafts 35. The shafts have their ends secured to the sides of the frame 3l), and are so positioned that thei upper edges of the supporting bars 33 are substantially flush with the top of the frame 30,

whereby a pair of flat bars 38, which are secured to the upper edges of the supporting bars 33' near their ends, move in a plane above said frame. The fiat bars 38 are so spaced that the bottom edge of the lowermost tray I may be secured to one of said bars while the vertical posts ll supporting the rear tray are suitably secured to the other flat bar, whereby the series of stepped trays is carried by the slidable carriage 33.

A U-shaped drive bar 36 has its inner ends secured to the slidable carriage 33 and its outer end journaled in one end of a pitman arm 3l. The other end of the pitman is journaled on the crank arm 32 of the crankshaft 32. A suitable pulley 52 is provided on one end of the crankshaft whereby a drive belt or other means (not shown) for rotating said crankshaft may be connected.

It will be seen, therefore, that when the crankshaft is rotated, it will act through the pitman arm 31 and the drive bar 36 to movethe carriage 33 reciprocally on the transverse shafts 35.

The bearings 34 may be made of any suitable material, such as babbitt or the like, but it is preferable that they be constructed as hereinafter described. As clearly shown in Figures. 5 and 6,

keach bearing is made of wood and includes an upper half ll which is securely i'lxed to the supporting bars by bolts 4I and has a suitable recess 112 provided in its bottom face for receiving the shaft 35. The lower half 43 of the bearing is formed with a recess 0.4 in its upper face for receiving the shaft 35, and is provided with ver- -tically extending slots 45 through which bolts 46,

nuts may be drawn up to move the lower half of the bearing into closer engagement with the shaft.

The shafts 35 are provided with suitable lubri eating connections 49 on one end, whereby a lubricant may be injected into the shaft and pass through openings 50 therein to lubricate the bearings sliding thereon. Suitable dust sleeves I are provided for the shafts.

It will be seen that since the device may be readily constructed of wood, pipe or other suit-- able material, manufacture is made economical and maintenance simple. Ihe simple structure also makes for a portable device which may be easily assembled.

It is noted that by varying the spacing of the baflles Within the trays, varying the height of the Walls of the trays, and also varying the angle of inclination of the series of trays, the device may be used to separate different kinds of materials.

It is further noted that, due to the stepped arrangement of the trays and the disposition of the bales within said trays, separation of diy material is accomplished without the use of water or other fluid to aid in the separation. This is a feature of the invention, since water or other fluid may not be available or desirable in some instances.

What I claim and desire to secure by Letters Patent, is:

1. A dry concentrator including, a plurality of transversely stepped closely arranged longitudinally elongate trays mounted to reciprocate longitudinally in a fixed horizontal plane, and a plurality of transverse partitions secured in each tray and extending from the rear wall to the front wall but spaced from the bottom of thetray with the top thereof substantially level with the top of the lower Wall of the tray.

2. A dry concentrator including, a plurality of transversely stepped closely arranged longitudinally elongate trays mounted to reciprocate longitudinally in a fixed horizontal plane, and a plurality of transverse foraminous partitions secured in each tray and extending from the rear wall to the front wall with the top thereof substantially level with the top of the lower wall of the tray.

3. A dry concentrator including, a plurality of transversely stepped closely arranged longitudinally elongate trays mounted for longitudinal reciprocation, the rear wall of one tray extending up to constitute the front wall of the tray stepped next above, and a plurality of transverse partitions secured in each tray and extending from the rear wall to the front wall but spaced from the bottom of the tray with the top thereof substantially level with the top of the lower wall of the tray.

4. A dry concentrator including, a plurality of transversely stepped closely arranged longitudinally elongate trays mounted for longitudinal reciprocation, the rear wall of one tray extending up to constitute the front wall of the tray stepped next above, and a plurality of transverse partitions secured in each tray and extending from the rear wall to the front wall but spaced from the bottom of the tray with the top thereof substantially level with the top of the lower wall of the tray, the transverse partitions being relatively staggered in the respective adjoining trays.

5. A dry concentrator including, a plurality of receiving trays arranged in stepped order one above the other, means for imparting a longitudinally reciprocating movement to the trays, and transverse partitions within and carried by each tray the tops of said partitions being substantially ush with the lower wall of the tray, for substantially overcoming the inertia of the major portion of the material over-riding the trays.

6. A dry concentrator including, a plurality of receiving trays arranged in stepped order one c above the other, means for imparting a longitudinally reciprocating movement to the trays, and transverse partitions within and carried by each tray the tops of said partitions being substantially ush with the lower wall of the tray, for substantially overcoming the inertia of the major portion of the material over-riding the trays, the partitions in each` adjoining tray being arranged in staggered relation.

JOSEPH G. WILSON. 

